Need to restart Configuration validating webhook when certificates are rotated

[johnsonshih]

We need a way for the webhook server to refresh certs when certificates rotated. Right now, the certs are read at start up and won't be refreshed so when certs retated, webhook still use old certs. Users have to manually restart the webhook pod for the webhook to pick up the new certs. It's not ideal.

[yujinkim-msft]

switching to kube-rs will affect how this may be addressed: #375

[github-actions]

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